Power shovel



March 19, 1940. c, E, STI HL Re. 21,405

POWER SHOVEL Orizinal Filed Sept. 18, 1937 I5 Sheets-Sheet l INVENT OR.

AHORNEYIS C. E. STIEHL POWER SHOVEL March 19, 1940.

3 Sheets-Sheen Original Filed Sept. 18, 1937 INVENTOR.

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ATTORNEYS,

C. E. STIEHL POWER SHOVEL Much 19, 1940.

Original Filed Sept. 18, 1937 3 Sheets-Sheet 5 r m m 5i. n r I f u r 2 tu I I L- Ca M QYZZEZL INVENTOR.

d B Wow- ATTORNEYS.

Reiuued Mar. 19, 1940 )1 UNITED STATES PATENT OFFICE POWER SHOVELOriginal No. 2,140,460 dated December 13, 1938,

Serial No. 164,454, September 18, 1937.

November 3, 1939, Serlalplication for reissue No. 302,727

8 Claims.

My invention relates to new and useful improvements in power shovels,and more particularly power shovels of the type having a boom and anoutward digging dipper mounted on the end of a handle, which handle isreciprocable with respect to a point on the boom known as the shippershaft, the dipper being movable in a circular are about this point as acenter.

The saddle block is that portion of the assembly which holds the dipperhandle to the shipper shaft, and through which the dipper handlereciprocates.

The dipper in digging encounters two sorts of stresses which have thusfar presented almost insuperable problems in shovel design. The first ofthese is an uneven downward pressure of the bank upon the twofrontcorners of the dipper. The second of these is a sideward push upon thedipper; this latter occurs not only during digging, but also duringacceleration and deceleration of the swinging cycle; this sideward pushwill be referred to as side-thrust."

If the handle be built narrow, to pass through a divided boom, a sidethrust on the dipper is apt to tear the boom apart. If, on the otherhand, the handle be built in two parts, straddling the boom, its sidethrusts and twists would impart a twist to the boom. To meet theseobjections,

various expedients have been adopted in the past,

such as building the boom with a spring foot, and/or widely supportingthe boom at its outer point and at the shipper shaft, either with orwithout some interlock between these two support means. But none ofthese expedlents has been wholly satisfactory.

Accordingly it is the principal object of my present invention toprovide a novel form of construction of the front and equipment of apower shovel, so that the digging strains will be transmitted to thoseparts of the machine best able to stand them, and be resisted at suchpoints.

A further object of my present invention is to provide a dipper handleand a resilient saddle block mounting therefor, so contrived anddesigned as to form one of the elements of my main combination.

In addition to this principal object, I have worked out a number ofnovel and useful details, which will become readily evident as thedescription progresses.

My invention is deslgned to combine all of the advantages with none ofthe disadvantages of the expedients of the prior art.

To accomplish this end, I combine four features, namely: (1) a freelyswivelabl'e dipperthe saddle-block, moreover, tends to restore thehandle to the plane of the boom. The rope thrust eliminates unevenpresentation of the handle to its crowding means, which unevenpresentation would otherwise largely offset the advantages gained by thejust-mentioned flexibility. And the twin hoist-ropes serve'to steady thehandle against twisting, and yet do not impart any twisting strain tothe boom.

A fairly satisfactory subcombination would consist in items 1,3 and 4,with item 2 as a very desirable addition.

Another fairly satisfactory sub-combination would consist in items 1, 2and '4, with item 3 as a very desirable addition.

Also I wish to claim specifically the details of item 2. I

My invention consists in the novel parts, andin the combinations andarrangements thereof, which are defined in the appended claims, and ofwhich one embodiment is exemplified in the accompanying drawings, whichare hereinafter particularly described and explained.

Throughout the description, the same reference number is applied to thesame member or to similar members.

Figure 1 is a side elevation of a power shovel embodying my invention.

Figure 2 is a plan viewof the boom, handle and ropes of my invention,taken along the line 2-2 of Figure 1.

Figure 3 is a plan view, partly in section, of the saddle block and partof the boom andhandle of Figures 1 and '2, taken along the line 3-3 ofFigure 4.

Figure 4 is a side elevation of these parts, taken the propelling baseof a power shovel, on which is mounted the revolving irame l2. Thislatter carries a boom hoist winch II, a dipper hoist winch i4, and adipper thrusting winch ll.

Winch I3 manipulates the widely spaced boom suspension cables Ii. Winchll manipulates twin hoist ropes l'l. Each of these ropes passes over oneof four boom point sheaves ll, around one of a pair of widely spacedsheaves attached to the dipper l9, and back over one (preierablyanother) of the sheaves II to the winch. This doubles and equalizes eachrope.

The dipper I9 is carried on the outer end of'a tubular handle 2|, whichslides in the saddle block, to be hereinafter described, mounted on theboom 2|. Winch l5 manipulates thrust rope 22, attached to the rear endof handle 2|, and retracting rope 23, attached to the front end 01'handle 20.

As already stated, the use of this means of thrusting and retractingpermits the handle to swivel in the saddle block, without introducingany problems of proper interaction oi the thrusting parts on the boomwith the thrusted parts on the handle.

Turning now to Figures 3 to 5. we see that the above-mentioned saddleblock consists of a hollow member 24, of rectangular cross-section, thebottom 01' which is appropriately slotted to receive roller 25, whichrevolves about shipper shaft 26. The top and bottom of member 24 eachterminates in two headed yokes 21, making four such yokes in all. Thesides of member 2| depend to form bearings 28, to support the member onthe shipper shaft 26.

The shipper shaft 26 is in turn supported from boom 2| by brackets 29.

Each pair of yokes 21 supports, by means of bolts 3. and springs ll, twocurved pieces 32, each oi which carries a bearing plate It, to bearagainst the sides of the handle 2..

Ropes 22 and 23 pass over sheaves 34, carried by the shipper shait 26.

Turning now to Figures 6 and '1, we see how, when a side thrust isimparted to the dipper, and thereby the handle 20 is thrown sidewardly,the resiliency oi the saddle block permits this movement, withoutimparting undue strains to the saddle block assembly, and thence to theboom.

0! course it is to be understood that, from the viewpoint of my broadgeneral combination, other forms of resilient saddle block might beused, and even a non-cylindrical handle, provided that it is permittedin some way to swivel, as by having it reciprocate in a cylindricalguide member within a saddle block similar to that described above.

Any twist on the handle 20, imparted by an uneven pressure on one or theother i'ront corner of the dipper, is, due to the cylindricality of thehandle 20, borne solely by the widely spaced twin hoist-ropes ll.

Having now described and illustrated one form of my invention, I wish itto be understood that my invention is not to be limited to the specificform or arrangement of parts hereinbei'ore described, except in so faras such limitations are specified in the appended claims.

This application is a continuation-in-part, as to all commonsubject-matter, ofmy copendin'g application, Serial No. 78,670, filedMay 8, 1936, for improvements in power shovels, which application nowstands allowed under date of May 21, 1937, and which has now beenpermitted to'lapse without prejudice, in view 01' its supersession bythis present application.

I claim: 1. In a power shovel, the combination of: a base; a boom,inclined forwardly therefrom; a hoist winch supported by the base; athrust winch supported by the base; a handle, mounted on the boom forreciprocation, and for angular movement in a vertical plane about aflxed' point on the boom; a digging dipper carried at the outer end ofthe handle; means supporting the handle at the above-mentioned point fortree turning about the handle axis, while resiliently resistingside-thrust; flexible tension members, actuated by the thrust winch anddirectly applied to the handle, for reciprocating the handle;

twin sheaves, laterally widely spaced at the outer end of the boom; andtwin flexible hoist members supporting the dipper at laterally widelyspaced points, and thence passing over the twin sheaves to the hoistwinch.

2. A power shovel, according to claim 1, characterized by the furtherfact that the handle is cylindrical.

3. In a power shove], the combination of: a base; a boom, inclinedforwardly therefrom; a hoist winch supported by the base; a handle,mounted on the boom for reciprocation, and for angular movement in avertical plane about a flxed point on the boom; a diggingdipper carriedat the outer end of the handle; means supporting the handle at the flxedpoint for free turning about the handle axis, while resilientlyresisting side-thrust; twin sheaves, laterally widely spaced at theouter end of the boom; and twin flexible hoist members supporting thedipper at laterally widely spaced points, and thence passing over thetwin sheaves to the hoist winch.

4. A power shovel, according to claim 3, characterized by the furtherfact that the handle is cylindrical.

5. In a power shovel, the combinaion of: a base; a boom, inclinedforwardly therefrom; a hoist winch supported by the base; a thrust winchsupported by the base; a handle, mounted on the boom for reciprocation,and for angular movement in a vertical plane about a flxed point on theboom; a digging dipper carried at the outer end of the handle; meanssupporting the handle at the above-mentioned point for free turningabout the handle axis; flexible tension members, actuated by the thrustwinch and directly applied to the handle, for reciprocating the handle;twin sheaves, laterally widely spaced at the outer end of the boom; andtwin flexible hoist members, supporting the dipper at laterally widelyspaced points, and thence passing over the twin sheaves to the hoistwinch.

6. A power shovel, according to claim 5, characterized by the furtherfact that the handle is cylindrical.

7. In a power shovel, the combination of: a base; a boom, inclinedforwardly therefrom; a cylindrical handle, mounted on the boom forreciprocation, and for angular movement in a vertical plane about afixed point on the boom; :1. digging dipper carried on the outer'end oithe handle; and a. saddle-block assembly, supporting the handle at theabove-mentioned point, and made up of the following parts: a shippershaft, carried by the boom; a handle-supporting roller, journaled on theshipper shaft; a hollow saddle block member, materially larger incross-section than the cross-section of the handle; a pair of curvedhandle guides, laterally spaced at each end of the hollow member; andlaterally yieldable resilient means whereby the member supports theseguides.

8. In a power shove], the combination of: a base; a boom, inclinedforwardly therefrom; a. handle, mounted on the boom for reciprocation,and for angular movement in a vertical plane about a fixed point on theboom; a digging dipper carried on the outer end of the handle; and asaddle-block assembly, supporting the handle at the above-mentionedpoint, and made up of the following parts; a shipper shaft, carried bythe boom; a handle-supporting roller, journaled on the sh pper shaft; asaddle block member; a.

pair of handle guides, laterally spaced at each 5 end of the member; andlaterally yieldable resilient means, whereby the member supports theseguides.

CARL E. STIEHL.

